1. Field of the Invention
This invention relates to the use of special glycoside esters as emulsifiers for the production of cosmetic and/or pharmaceutical formulations.
2. Description of the Related Art
The production of cosmetic and pharmaceutical formulations, for example creams, lotions and salves, generally entails the use of aqueous and oily constituents which are not readily miscible with one another. It is only the addition of suitable emulsifiers which enables stable emulsions of the water-in-oil or oil-in-water type to be formed. The emulsifiers may be selected from a range of substances which are capable of reducing interfacial tension. Typical examples are fatty acid partial glycerides, polyglycerol esters, alkyl polyglucosides, fatty alcohols and the like. In many cases, the production of stable emulsions is dependent upon the careful choice of a suitable emulsifier system even though modern formulation techniques can be helpful in this regard (cf. for example C. Cabeza et al. in SOFW-Journal 120, 162 (1994) and A. Ansmann et al. ibid 120, 158).
Nevertheless, the product developer is often left with no alternative but to select the appropriate emulsifier(s) from a range of suitable emulsifiers for a specific formulation. If different emulsions are to be produced, this means that a number of emulsifiers have to be kept available which involves expensive and, hence, unwanted storage.
Another problem is that, although certain emulsifiers are capable of reliably ensuring emulsion formation, they do not have a thickening effect, i.e. additional viscosity-increasing substances have to be added where it is desired to build up a high viscosity (for example in a cream). Alternatively, natural waxes, for example beeswax, may also be used although they are expensive and are difficult to process.
Accordingly, the problem addressed by the present invention was to provide new "all-round" emulsifiers which would make it possible to produce both o/w and w/o emulsions and which, at the same time, would build up a satisfactorily high viscosity in the emulsions so that it would no longer be necessary, for example, to use expensive natural waxes.